Maddison took his KTM 450 out for a spin across the muddy brown surface of the river on Thursday morning, as you do; well, it's one way to beat the peak-hour rush. He rode 1.7 kilometres at an average speed of about 70km/h. When he got back to the riverbank, he dried off and did it again.

"This was my first time doing it as a public thing," the 35-year-old stunt rider, originally from Kiama, in New South Wales, but now based in the US, told Fairfax once he was back on terra firma. "It was really special for me to bring the water bike to Australia for the first time."

But Maddison's ride was no Christmas miracle, more a case of engineering moving in mysterious ways. His bike is equipped with water skis attached to each wheel. It sports a specially adapted hill-climbing tyre on the rear wheel, with massive rubber knobs that scoop water out behind and propel the bike forward. "It works exactly like the wheel of a paddle steamer," he explains.

It's not the first time the former FMX (freestyle motocross) rider has traded dirt for water. In 2015, he took his bike to the waves in Tahiti, in a stunt labelled "Robbie Maddison's Pipe Dream". Even now he's working on a Pipe Dream 2, which he plans to film as soon as conditions are right. "We're just waiting for a monster swell off the coast of Mexico."

That Tahiti ride was three years in the planning, but a lifetime in the dreaming. "I've wanted to do this since I was a little kid," he says.

The Yarra run was set up in a mere six weeks. In fact, Maddison was so busy working on Pipe Dream 2 that he only arrived in Australia on Wednesday afternoon. No time for a practice run; indeed, one missed connection and the whole thing would have fallen over.

The stunt was staged in part to publicise the upcoming film xXx: The Return of Xander Cage, in which Maddison doubles for Vin Diesel in the motorcycle sequences, including one in which Diesel rides (or appears to ride) his bike across water. It's Maddison's second film outing, the first coming in Skyfall, where he performed the bike stunts for Daniel Craig. His next is in an ad for Ralph Lauren, in which he doubles for Australian actor Luke Bracey, star of the Point Break remake.

Inspired by Evel Knievel, Maddison holds a clutch of distance records - including longest ramp-to-ramp jump, and highest jump. But he retired recently from the FMX circuit on the advice of his doctor, who was, he says, "a bit worried about all those knocks on the head".

Not that the water bike is without its dangers. In July, a man named Blake Becker died in Montana while attempting to cross a lake on his motorcycle; it appears he may have become tangled in the safety equipment that was meant to keep him alive.

"I really want to stress this: don't try this at home," says Maddison. "I've nearly drowned a few times. I rode a 20-foot wave in Tahiti and got hit in the back by my bike. I wasn't able to breathe; it was only the air balloons that saved me."

In getting to this stage, he admits to having sunk "a lot of bikes - I couldn't even give you a number. On Triple X we killed 12 bikes", in preparing for the Tahiti ride, he told Wired last year, he sank over 100 times.

Impressive as his waterborne stunts are, Maddison insists they are no more than works in progress.

"We have a vision for this thing," he says. "We're not even halfway there yet."

Karl Quinn is on facebook at karlquinnjournalist and on twitter @karlkwin